Generally, a semiconductor manufacturing process is classified into a pre-process (fabrication-process) and a post-process (assembly process). The pre-process means process for manufacturing a semiconductor chip by forming predetermined patterns through repeated processes of depositing a thin film on a wafer within a variety of process chambers, and selectively etching the deposited thin film. The post-process means process for assembling a completed product by separating the chips manufactured in the pre-process into individual chips, and coupling the separated chips to lead frames. At this point, the process of depositing a thin film on the wafer or etching the thin film deposited on the wafer is performed within the process chamber at high temperature using toxic gases such as silane, arsine, and boron trichloride, and a process gas such as hydrogen. During the pre-process, a large amount of various combustible gases, corrosive foreign substances, and a toxic gas containing a toxic component is generated inside the process chamber.
Therefore, a semiconductor manufacturing equipment includes a scrubber at a rear end of a vacuum pump for generating a vacuum state in the process chamber. The scrubber purifies an exhaust gas discharged from the process chamber and discharges the purified exhaust gas to atmosphere. However, when an exhaust gas discharged from the process chamber contacts the atmosphere or a surrounding temperature is low, the exhaust gas solidifies and changes into powder. The powder sticks on an exhaust line to increase an exhaust pressure, and simultaneously, causes a disorder of the vacuum pump when it is introduced to the vacuum pump, and causes a back flow of an exhaust gas to contaminate a wafer located inside a process chamber.
To solve this problem, a powder trap unit for changing an exhaust gas discharged from a process chamber 1 into a powder state is installed between the process chamber 1 and a vacuum pump 2 as illustrated in FIG. 14. That is, as illustrated in FIG. 14, the process chamber 1 is connected with the vacuum pump 3 via a pumping line 5. A trap pipe 7 for trapping and piling reaction-byproduct generated at the process chamber 1 in the form of powder branches from the pumping line 5.
In a conventional powder trap unit, a non-reacted gas generated while a thin film is deposited or etched within the process chamber 1 flows to the pumping line 5 having a relatively low temperature atmosphere compared to that of the process chamber 1, so that the non-reacted gas solidifies into powder 9, and is accumulated in the trap pipe 7 branching from the pumping line 5.
However, the above-described conventional powder trap unit has the following problems.
First, since it takes a long time until reaction-byproducts generated within the process chamber change into powder and are accumulated in the trap pipe, a turn around time (TAT) is lengthened as much as that. That is, a next thin film deposition or etching process is not performed until reaction-byproducts generated when a thin film is deposited or etched swiftly changes into powder and are accumulated in the trap pipe, but it takes a long time for the reaction-byproducts to change into powder. Accordingly, the process chamber cannot perform a next process until all of to the reaction-byproducts are removed and stands by for a long time. Therefore, not only an operating rate of an equipment reduces, but also a TAT is lengthened due to a long standby time of the process chamber. Second, since a collecting area (space) of a trap pipe in which powder is accumulated is very narrow, there has been inconvenience of having to frequently removing powder accumulated in the trap pipe. Particularly, since powder is concentrated and accumulated only in an entry of the trap pipe, a cleaning period of the trap pipe is short.